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Diffstat (limited to 'Documentation/kbuild/Kconfig.select-break')
| -rw-r--r-- | Documentation/kbuild/Kconfig.select-break | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/Documentation/kbuild/Kconfig.select-break b/Documentation/kbuild/Kconfig.select-break new file mode 100644 index 000000000000..365ceb3424b1 --- /dev/null +++ b/Documentation/kbuild/Kconfig.select-break @@ -0,0 +1,33 @@ +# Select broken dependency issue +# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +# +# Test with: +# +# make KBUILD_KCONFIG=Documentation/kbuild/Kconfig.select-break menuconfig +# +# kconfig will not complain and enable this layout for configuration. This is +# currently a feature of kconfig, given select was designed to be heavy handed. +# Kconfig currently does not check the list of symbols listed on a symbol's +# "select" list, this is done on purpose to help load a set of known required +# symbols. Because of this use of select should be used with caution. An +# example of this issue is below. +# +# The option B and C are clearly contradicting with respect to A. +# However, when A is set, C can be set as well because Kconfig does not +# visit the dependencies of the select target (in this case B). And since +# Kconfig does not visit the dependencies, it breaks the dependencies of B +# (!A). + +mainmenu "Simple example to demo kconfig select broken dependency issue" + +config A + bool "CONFIG A" + +config B + bool "CONFIG B" + depends on !A + +config C + bool "CONFIG C" + depends on A + select B |